Patent GB-713949-A (GB)
Title: Improvements in or relating to a tire building machine
IPC: B29D30/28
Filed: 1951-04-20
Abstract: 713,949. Tyre building machines. FIRESTONE TIRE & RUBBER CO. April 20, 1951 [April 27, 1950], No. 9259/51. Class 144(1) A stitcher unit for use in a " flat-band " tyre building machine, wherein the under and over plies are stitched around the beads comprises a roller stitcher 188 which is rotatably mounted on a shaft 189 pivoted on a stitcher support 196 rotatably mounted in a crank arm 103 which is in turn adapted for journal mounting, the pivoted shaft 189 swinging about an axis transverse to the axis of rotation of the support 196. As shown, Fig. 1, the machine comprises the usual rotary collapsible building drum 2 mounted on a cantilever shaft 6 which supports an axially slidable bead-applying' ring 7. The other bead-applying ring 32 is carried on an arm 33 which is slidable axially of the drum, the ring 32 having a central sleeve portion 35 to engage over a pin 40 on the drum shaft for centring purposes. The ply-turning roller stitcher structures are mounted at the rear of the drum 2 on blocks 76, Fig. 2, which are pivotally supported on a shaft 69 parallel with the drum 2 and are keyed to brackets interconnected by a platform 73. The angular position of the blocks 76 on the shaft 69 is adjustable by nuts 91 clamping a bracket 83, secured to the platform 73, to an eye-bolt 86 secured to a pedestal 66. Each block 76 rotatably supports a shaft 92, Fig. 4, which is driven by a wormwheel 107 and worm 113 from a motor 119 bolted to one of the blocks 76. The two worms 113 for the two stitcher units, are connected by a telescopic shaft to allow for relative axial adjustment of the blocks 76 for different length drums. Each shaft 92 has keyed to its top one end 102 of a crank arm 103 the other end 154 of which is radially offset and rotatably supports the lower end of a stitcher support 196. The support 196 has keyed to its bottom a pinion 163 which is engaged by a rack 169 pneumatically operated by means of a cylinder 171 fed through an axial bore 137 in the shaft 92. The cylinder 171 is single acting and operates the rack 169 to turn the support 196 against the action of a helical spring 181. Pivoted in the top of the support 196 transversely of the axis of the shaft 92. is a block 192 in which is clamped a shaft 189 upon which the roller stitcher 188 is mounted. The pivotal movement of the block 192 is limited by adjustable stop screws 201, 202. The roller stitcher 188, Fig. 6, is formed in two parts 208, 209, the outer part 209 being secured against axial movement and comprising a cylindrical portion 212 and a rounded outer annular flange 211. The inner part 209 is axially movable on its shaft 189 and is recessed to fit over the part 208 so that its outer conical portion 190 forms a continuation of the flange 211 of part 208, a spring 228 normally urging the part 209 over the part 208. In operation the blocks 76 are angularly adjusted on shaft 69 so that shafts 92 lie tangential to the drum 2. With a bead 233 applied to the underplies 231, 232 as shown in Fig. 8, the shaft 92 is rotated to swing crank arm 103 and stitcher support 196 around to bring the roller stitcher 188 radially inwardly of the bevelled drum end 249. The support 196 is then rotated against its spring 181 to bring the stitcher part 208 against the underplies 231, 232, Fig. 9, when the shaft 92 is rotated in the opposite direction from its previous movement to cause the stitcher 208 to roll the underplies upwardly around the beads. During this operation the drum rotation is as indicated in Fig. 6 and this causes the stitcher shaft block 192 to be pivoted downwardly to the position limited by stop screw 201. This angular setting of the stitcher roller and the rotational direction of the drum holds the roller part 208 in its operative position over the part 209. On completion of the stitching of the underplies the stitcher support 196 is allowed to rotate under the action of its spring 181 to swing the roller out of contact with the plies. When the overplies 239, 241 are wound, the drum is rotated as indicated in Fig. 7 and the roller 208, 209 swung by its support 196 into engagement with the plies. This time the rotation of the drum causes the stitcher shaft block 192 to pivot upwardly to the position limited by screw 202 and the roller part 208 is forced back, on contact with the plies, to leave roller part 209 in operative position. Rotation of shaft 92 completes the stitching of the overplies, the flanged construction of the roller part 209 and the bevelled edge 249 of the drum allowing maximum range of movement of the stitcher, Fig. 13. In an alternative construction arranged to avoid the necessity of re-adjusting the stop-screws 201, 202 for each adjustment of the angular setting of the blocks 76, the blocks 76 and shaft 69 are relatively fixed and the platform 73 is arranged for slidable adjustment in inclined grooves in fixed end brackets carried by the pedestal 66 so that the whole stitcher structure can be moved to accommodate different diameter drums. Fig. 14 shows a shape of stitcher roller 208 suitable for use on large size tyres. Specification 552,116 is referred to.